This problem is really starting to annoy me, I own a pair of CDJ-900 and a CDJ-400.
First things first, I already put my tunes through rekordbox for the CDJ-900 USB, I had to, mainly because it gives me a retarded BPM reading when its not gone through rekordbox.
Right, so this is the issue here, my bpm pitch is ±10, that means it goes 1 BPM up when a tune reaches 0.40% increase. But the problem with some tunes regardless of BPM, some go up by 1 when it reaches 0.35%
One thing I realized today was tunes that are below 130 BPM go up 2 BPM up at 1.20%, 130-136 go up 2 BPM up at 1.15% and 138+ go up 2 BPM at 1.10%. At least thats how it is on my CDJ-400.
Does anyone ever have inaccurate BPM readings when using USB's? This never happens with CD's
EddieZilker
quote:
Originally posted by Amir_9
One thing I realized today was tunes that are below 130 BPM go up 2 BPM up at 1.20%, 130-136 go up 2 BPM up at 1.15% and 138+ go up 2 BPM at 1.10%. At least thats how it is on my CDJ-400.
Clearly, you're through the looking glass, so there's no point in keeping this problem relating to shoddy craftsmanship much of a secret, any more. For years, songs written in one tempo have been subject to this clearly arbitrary "pitch" adjustment "scheme". Using the pitch fader, in order to increase or decrease the speed of music playing, has relied on relatively little, if any, correlation to the actual tempo of the music. Now that you've blown the lid off of this scandal, maybe these insinuations that the fader is related to the BPM of the song instead of how fast the platter is spinning will finally come to a rest.
The reason they've fooled you into thinking that the pitch relates directly to the tempo is because it affects how quickly the song plays! This is something all the major manufacturers have tried to keep covered up! WHY?!?! Because, if Pioneer made a product where pitch was a static value proportionally related to the tempo of the music their products were playing, no one would ever buy it. Therefore, what Pioneer and numerous other manufacturers have done is to make a product where pitch is a variable proportionally related to the BPM of the music their products are playing!
WHAT ALLOWS THEM TO GET AWAY WITH SUCH PATENTLY FALSE ADVERTISING?
They claim that changing the Revolutions Per Minute (RPM) changes the Beats Per Minute (BPM) of the music playing on their faulty, bad, evil, vile, dangerous products!
It comes down to this disingenuous equation:
CAUTION: Discontinue
trying to figure
this out if you
feel dizzy, light-
headed, nauseous,
or if you develop
a head-ache, and
call your doctor or
poison control
center, immediately.
Tell them you have
been exposed to
beginner's algebra.
You SEE?!? It would have been impossible for them to have made a product where the pitch was a static value because it would never, in a million years, sell! Therefore, they made the BPM a static value while making RPM variable. In so doing, they could use this mathematical mumbo-jumbo to formulate an entirely theoretical new value for the BPM in the readout of these supposedly "accurate" machines.
THE MP3/FLAC SCANDAL!
Back in the old days, DJ's were relegated to how quickly a platter spun in order to change the speed of a record. Tempo was arbitrarily decided by musicians and producers. In order for a DJ to change the speed of the record, he'd have to change the speed of the record player spinning, normally, at 33.5 or 45 revolutions per minute. One would have thought that the advent of portable digital media formats would have released DJ's from using this draconian system of tempo control.
Unfortunately, musicians and producers, to this day are allowed to make completely arbitrary decisions about how quickly their musical events occur in relation to one another. While the platter, spinning at up to 10,350 RPM, on the cd player has been replaced with complex algorithms which track a frame-rate synchronized with a "word-clock" - whatever that means - the DJ is still relegated to controlling a pitch value, intrinsically related to the original tempo of the song. The worst part about frame rate and word-clock is that THEY ARE COMPLETELY UNRELATED TO THE ORIGINAL TEMPO THE MUSIC WAS RECORDED IN!
SELL THE HOUSE, SELL THE CAR, SELL THE CDJ's, FIND SOMEONE ELSE. FORGET IT. I'M NEVER COMING BACK. FORGET IT.
The end result is that there's no possible way to be sure, unless you play music which is either sixty or even one-hundred twenty beats per minute. With so much music being written in tempos well outside those two values, you'd have to have successfully completed the seventh grade with honors classes or have a tremendously good sense of rhythm to be able to consistently beat-match. It's practically impossible!
Looney4Clooney
the only thing i know about BPM involves my fist and my girlfriend's face.
Stu Cox
quote:
Originally posted by EddieZilker
Blah
What the hell are you talking about? Was that actually the biggest dose of sarcasm that anyone's ever laid in a single post, or are you actually off your rocker?
If a tune is 130 bpm... to go up 2 bpm to 132 is 132/130 = 1.015, i.e. +1.5%
If a tune is 140 bpm... to go up 2 bpm to 142 is 142/140 = 1.014, i.e. +1.4%
Simple as that.
Although when using the readouts, there will be a bit of variation, as a tune which says 130 bpm when at 0% could actually be anywhere between 129.5 and 130.5 bpm. Also, the readout will actually tick up to 132 at 131.5 (because it rounds it), so actually a track at '130' could tick up to '132' anywhere between +0.77% and +1.54%.
Similarly, a track at '140' on 0% could tick up to '142' anywhere between +0.71% and +1.43%.
So the numbers you've quoted are well within those bands.
The way it's implemented doesn't make any difference. And the revolution speed of a CD varies between 200 and 500 RPM, no idea where you got 10,350 RPM from.
EddieZilker
quote:
Originally posted by Stu Cox
What the hell are you talking about? Was that actually the biggest dose of sarcasm that anyone's ever laid in a single post, or are you actually off your rocker?
If a tune is 130 bpm... to go up 2 bpm to 132 is 132/130 = 1.015, i.e. +1.5%
If a tune is 140 bpm... to go up 2 bpm to 142 is 142/140 = 1.014, i.e. +1.4%
Simple as that.
Although when using the readouts, there will be a bit of variation, as a tune which says 130 bpm when at 0% could actually be anywhere between 129.5 and 130.5 bpm. Also, the readout will actually tick up to 132 at 131.5 (because it rounds it), so actually a track at '130' could tick up to '132' anywhere between +0.77% and +1.54%.
Similarly, a track at '140' on 0% could tick up to '142' anywhere between +0.71% and +1.43%.
So the numbers you've quoted are well within those bands.
The way it's implemented doesn't make any difference. And the revolution speed of a CD varies between 200 and 500 RPM, no idea where you got 10,350 RPM from.
Although when using the readouts, there will be a bit of variation, as a tune which says 130 bpm when at 0% could actually be anywhere between 129.5 and 130.5 bpm. Also, the readout will actually tick up to 132 at 131.5 (because it rounds it), so actually a track at '130' could tick up to '132' anywhere between +0.77% and +1.54%.
Similarly, a track at '140' on 0% could tick up to '142' anywhere between +0.71% and +1.43%.
So the numbers you've quoted are well within those bands.
The way it's implemented doesn't make any difference. And the revolution speed of a CD varies between 200 and 500 RPM, no idea where you got 10,350 RPM from.
The rounding off bit I'm aware of already, same goes with tracks that are 129.5 or 130.5 as you mentioned, as I already get the exact BPM of a track when I look for its key as well.
One thing is, I've never had problems with wrong BPM readings when using CD's. While the mistakes with USB's are minimal, they effect me either way, the two tracks will start off beatmatched just fine before they start to drift off.
At ±10 anyway, a 128 BPM track will get to 130 at 1.20% on the CDJ-400, but on my CDJ-900 that same track will end up at 130 on 1.10% or 1.15% sometimes, oddly enough the CDJ-400 gives the right BPM reading, when the rekordbox sync'd tunes on a newer product gives me the wrong reading.
Originally posted by Stu Cox
Alright, you can have that one :p
I can already see the headlines as the DJ and a few onlookers are injured when an optical drive shatters at a warehouse party, but you can see for yourself how dangerous these products really are.
:stongue:
idoru
Solution:
Amir_9
Took this video before I found out about rekordbox.
It looks like a difference in calculation related to the pitch-range of the fader. If you have one fader which raises the pitch ± one octave but the other raises pitch ± two octaves, you're going to see a difference in the percentage the faders related to the effect of their range.
CDJ 400 Tempo Control: Four tempo modes, ±6%, ±10%, ±16% and WIDE, provide additional speed control with a resolution of 0.02% in the 6% range.
The CDJ 900's web-material doesn't talk about tempo control or even what range the pitch control sits in. If it's ± one octave and the percentage you're seeing is a calculation off of a change you're making within that range, you may always see a difference in the percent change from one unit to another.
SYSTEM-J
quote:
Originally posted by Amir_9
Right, so this is the issue here, my bpm pitch is ±10, that means it goes 1 BPM up when a tune reaches 0.40% increase. But the problem with some tunes regardless of BPM, some go up by 1 when it reaches 0.35%
Erm... the 10 in ±10 is 10%, not 10bpm. I've no idea why you're getting a discrepency between decks, because your calculations should always be equally wrong. I can only think that one of the decks has inferior pitch resolution.
